STABILITY INDICATING ASSAY OF ORLISTAT AND ITS DEGRADATION PRODUCTS BY HPLC

A simple, selective, rapid, precise and economical RP-HPLC stability-indicating method has been developed and validated for the quantitative estimation of orlistat (API) and their degradation products. Chromatographic separation was accomplished using C18 column with mobile phase consisting of acetonitrile:0.1% formic acid (85:15, v/v), flow rate was 1.0 ml/min and the detection wavelength was 215 nm. The method was validated for linearity, accuracy, precision, specificity and robustness. The API was subjected to stress condition of acid decomposition (0.1 N HCl refluxed for 8 h at 80 degree celsius), alkali decomposition (0.1 N NaOH refluxed for 8 h at 80 degree celsius), neutral hydrolysis (Distilled water refluxed for 12 h at 80 degree celsius), oxidative decomposition (3% H2O2 for 24 h at RT), thermal decomposition (Drug at 100 degree celsius for 24 h), photolytic decomposition (70,000-80,000 lux at 7 days). Percentage of degraded products were 13.37, 9.23, 1.44 and 5.04 for acid, alkali, neutral hydrolysis and oxidative decomposition respectively. No degradation was observed in thermal and photolytic conditions. Forced degradation study showed that orlistat is labile in acid, alkali, neutral and oxidative conditions. It is stable to light and dry heat. No interference of degradation products was found at the retention time of principal peak. The assay can be recommended for analysis of the API and degradation products in stability samples. It may be applied to a routine analysis in industries.